Adhesive tape for tape automated bonding

ABSTRACT

An adhesive tape for TAB having an organic insulating film, an adhesive layer formed on the organic insulating film and a protection layer formed on the adhesive layer, the adhesive layer being any one of a layer containing a polyamide resin having an amine value of at least 3 and an epoxy resin, a layer containing a polyamide resin and a powdery inorganic filler, a layer containing an epoxy resin having a siloxane structure in its main chain, and a layer containing at least one maleimide compound.

This application is a division of application Ser. No. 08/612,264, filedMar. 7, 1996, (now U.S. Pat. No. 5,843,550), which is a division ofapplication Ser. No. 08/216,432, filed Mar. 23, 1994 (now U.S. Pat. No.5,523,137), which application is a division of now abandoned applicationSer. No. 07/917,345, filed Jul. 23, 1992.

FIELD OF THE INVENTION

The present invention relates to an adhesive tape for tape automatedbonding (hereinafter referred to as TAB). The adhesive tape for TAB isprocessed into a TAB tape for use in a process for manufacturingsemiconductor devices, in particular, those devices which require lowdimensional changes to suit high-pin count and fine patterned devices.

PRIOR ART

Heretofore, adhesive tapes for TAB have been processed into TAB tapes bythe method which comprises the following steps:

(1) punching the adhesive tape for TAB by stamping means to makesprocket and device holes and removing a protective film from thepunched tape,

(2) attaching copper foil on the removed portion of the punched tape bya thermocompression bonder and heating the copper-foil laminated tape toharden an adhesive therein,

(3) coating a photoresist on the copper-foil laminated tape, irradiatingthe photoresist with UV or the like through a mask, and developing thephotoresist with a developer,

(4) backing the device hole, etching the copper, eliminating the resist,de-backing the device hole, coating a solder resist on the copperfoil-laminated tape, and making a circuit on the copper-foil laminatedtape, and

(5) plating tin or gold on the tape to obtain a TAB tape.

A semiconductor chip is inner-lead bonded to the above-obtained TABtape, leads are cut (trimmed), and the assembly of the chip and the TABtape is outer-lead bonded to a substrate, etc., and sealed with a resin.Alternatively, after the assembly is inner-lead bonded to the TAB tape,the assembly is sealed with a resin, then the leads including leads forperipheral circuits are cut (trimmed), and the assembly is outer-leadbonded to a substrate.

Positioned between copper foil as a metal and an organic insulatingfilm, an adhesive used in an adhesive tape for TAB is required to havehigh adhesion strength to both the copper foil and the organicinsulating film. Conventional adhesive tape for TAB have the followingdefects. a) The adhesive shows a decrease in the adhesion strength to acopper foil since the adhesive layer is exposed to alkalis (e.g.,potassium ion at a gold plating time or at resist peeling time), acids(e.g., chloride ion or sulfate ion at a tin plating time) and an etchingsolution (containing chloride ion) in the above steps. b) The insulationreliability decreases since the above alkalis and acids are absorbedinto, and stored in, the adhesive layer. c) The adhesion strength of theadhesive to the copper foil and organic insulating film decreases at ahigh temperature when the above inner lead bonding and outer leadbonding are carried out. d) A copper foil pattern sinks into theadhesive layer during the above bonding procedures, the tape thicknessbecomes nonuniform. As a result, with an advance in the device densityand an increase in the number of input and output terminals, there ariseproblems of bonding failure in a multi-terminal device, lead deformationand peeling.

The adhesive layer and organic insulating film of the adhesive tape forTAB are often allowed- to remain in a peripheral circuit and a sealingresin. In this case, with an advance in the device density, there arisesa problem of ionic impurities which affect the copper foil interpatterninsulation reliability and corrode an A1 circuit. The ionic impuritiesare derived mainly from the adhesive. That is, the ionic impurities areformed since the adhesive layer is exposed to alkalis, acids and anetching solution in the above steps 3) to 5), or they are contained inthe adhesive per se. The insulation reliability is affected by theresistance of the adhesive to moist heat, the electric resistance of theadhesive and the above ionic impurities.

Conventional adhesives used in adhesive tapes for TAB areepoxy-containing adhesives. These adhesives cause a problem ofinsulation deterioration, including inter-lead migration of a metal in alead pattern, due to the following properties which the adhesives have.That is, (a) the adhesives are liable to absorb ionic impurities(particularly chloride ion) when the tape is processed, (b) theadhesives are liable to be hydrolyzed due to moist heat, and (c) theadhesives have low electric resistance.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an adhesive tape forTAB which is excellent in chemical resistance and heat resistance in animplementation process and which has high adhesion strength.

It is another object of the present invention to provide an adhesivetape for TAB which is almost free from insulation deterioration andalmost free from corrosive action.

According to the present invention, there is provided an adhesive tapefor TAB having an organic insulating film, an adhesive layer formed onthe insulating film and a protection layer formed on the adhesive layer,the adhesive layer being any one of a layer containing a polyamide resinhaving an amine value of at least 3 and an epoxy resin, a layercontaining a polyamide resin and a powdery inorganic filler, a layercontaining an epoxy resin having a siloxane structure in its main chain,and a layer containing a maleimide resin.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross-sectional view of an adhesive tape for TABaccording to the present invention.

FIG. 2 is a chart showing the production of an adhesive tape for TABaccording to the present invention.

FIG. 3 is a schematic cross-sectional view of another adhesive tape forTAB according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically show the cross section of a tape of the presentinvention, in which a thermosetting, semi-cured adhesive layer 2 isformed on an organic insulating film 1, and a protection film 3 as aprotection layer is formed on the adhesive layer 2. The adhesive layer 2in FIG. 2 has a one-layer structure, while it may have a multi-layerstructure.

The organic insulating film has a thickness of 25 to 188 μm, preferably50 to 125 μm. The organic insulating film is selected from aheat-resistant film formed of polyimide, polyetherimide,polyphenylenesulfide or polyether ether ketone, and a compositeheat-resistant film formed of an epoxy resin and a glass cloth, or anepoxy resin, polyimide and a glass cloth.

The adhesive layer is thermosetting, and is required to be in asemi-cured state. The adhesive layer is formed of at least one layer.The thickness of the adhesive layer is in the range of from 5 to 50 μm,preferably in the range of from 15 to 30 μm.

The adhesive layer is in contact with the organic insulating film.Therefore, the adhesive layer is required to have high adhesion strengthto the organic insulating film even at a high temperature, high adhesionstrength to a copper foil and excellent chemical resistance to chemicalsto which the adhesion layer is exposed when it is processed to form aTAB tape.

To satisfy the above requirements, the present invention (to be referredto as the present invention 1 hereinafter) provides an adhesive tape forTAB having an organic insulating film, an adhesive layer formed on theorganic insulating film and a protection layer formed on the adhesivelayer, in which the adhesive layer contains a polyamide resin having anamine value of at least 3 and an epoxy resin. The polyamide resin isincorporated in order to achieve the adhesion of the adhesive layer tothe organic insulating film and flexibility. In the present invention 1,the amine value of the polyamide resin is required to be at least 3, andit is preferably 5 to 50. When the polyamide resin has a high aminevalue, the reactivity and affinity of the polyamide resin with the epoxyresin co-present in the adhesive are improved. As a result, the curedadhesive layer shows improved adhesion strength, improved chemicalresistance and improved heat resistance. When the above amine value isless than 3, the reactivity of the polyamide resin with the epoxy resinis too low. As a result, there is no effect on the improvement in theadhesion strength to the organic insulating film and a copper foil, andthe resultant tape fails to satisfy the chemical resistance required foretching and plating and the heat resistance required for bonding.

The amine value of the polyamide resin refers to a milligram weight ofKOH equivalent to the weight of an amine alkali present in 1 g of apolyamide resin sample. It is obtained by dissolving a polyamide resinin a toluene/n-butanol (1/1) mixed solvent and neutralization-titratingthe so-prepared mixture with a 0.5N hydrochloric acid aqueous solutionas a titration liquid in the presence of an indicator.

The polyamide resin used in the present invention 1 is selected fromaliphatic polyamides and aromatic polyamides having a weight averagemolecular weight of 2,000 to 150,000 and a softening temperature of 50to 180° C.

The epoxy resin used in combination with the polyamide resin reacts witha terminal of the molecular chain of the polyamide resin to improve theheat resistance and chemical resistance. The epoxy resin is used in anamount of 9 to 88 parts by weight per 100 parts by weight of thepolyamide resin.

In the present invention 1, the adhesive layer preferably contains animidazole compound in addition to the epoxy resin. The epoxy resineasily reacts under the action of the imidazole compound to furtherimprove the heat resistance and chemical resistance.

The adhesive layer in the present invention 1 may further contain aphenolic resin. The phenolic resin is incorporated preferably in anamount of 5 to 60 parts by weight per 100 parts by weight of thepolyamide resin. Further, the adhesive layer may additionally contain apolyester resin and thermoplastic resins such as acrylonitrile-butadienerubber (hereinafter referred to as NBR) and styrene-butadlene rubber(hereinafter referred to as SBR).

As a first variant, the present invention (to be referred to as thepresent invention 2 hereinafter) provides an adhesive tape for TABhaving an organic insulating film, a thermosetting adhesive layercomposed mainly of a polyamide resin and formed on the organicinsulating film, and a protection layer formed on the adhesive layer, inwhich the adhesive layer contains at least one powdery inorganic filler.

FIG. 3 shows the schematic cross-sectional view of an adhesive tape forTAB according to the present invention 2, in which a semi-cured adhesivelayer 2 containing a powdery inorganic filler 4 is formed on one surfaceof an organic insulating film 1, and a protection film 3 is formed onthe adhesive layer. In the present invention 2, the adhesive layer iscomposed mainly of a polyamide resin and contains at least one powderyinorganic filler. In order to impart the tape with chemical resistance,it is preferred to incorporate a phenolic resin and an epoxy resin as athermosetting component into the adhesive layer. When an epoxy resin isincorporated, it is preferred to use an accelerator such as an imidazolecompound in combination. Further, the adhesive layer may further containa polyester resin and thermoplastic resins such as NBR and SBR.

The powdery inorganic filler used in the present invention 2 works toinhibit the thermal expansion and contraction of the adhesive layer. Thepowdery inorganic filler is selected from stable oxides such as powderedsilica, alumina, diatomaceous earth, titanium oxide, zinc oxide andmagnesium oxide, and other inorganic pigments. The powdery inorganicfiller preferably has an average particle size of 0.1 to 30 μm. Theaverage particle size is obtained by measurement using a lighttransmitting particle size analyzer.

In the present invention 2, the amount of the polyamide resin based onthe total solid content of the adhesive layer is preferably 7 to 80% byweight. When this amount is less than 7% by weight, the adhesive isliable to ooze out of a line formed between the adhesive layer and thecopper foil and out of a device hole. When the above amount exceeds 80%by weight, the adhesion strength to the copper foil decreases. Thecontent of the powder inorganic filler in the adhesive layer is 1 to 90%by weight, particularly preferably 3 to 50% by weight. When this contentexceeds 90% by weight, the adhesive layer sometimes shows insufficientadhesion strength to a copper foil when the copper foil is bonded to theholed tape under heat and pressure. In some cases, the adhesive per seturns opaque to impair the visibility through the tape in positioningwhen the bonding is carried out. When the above content is less than 1%by weight, no sufficient effect of the powdery inorganic filler can beexpected.

In the present invention 2, when the adhesive layer is formed of twolayers or more, the layer in contact with the protection film isrequired to contain the powdery inorganic filler.

The polyamide resin used as a main component of the adhesive layer isselected from a variety of known polyamide resins. The molecular weightof the polyamide resin has something to do with flexibility and meltingproperties (oozing of the adhesive out of a device hole) when theadhesive layer is bonded to a copper foil under heat and pressure andwhen the adhesive is cured. When the molecular weight of the polyamideresin is too low, the melting temperature is too low and the problem ofthe adhesive oozing occurs. When this molecular weight is too high, toohigh a temperature is required to bond the adhesive layer to a copperfoil under pressure. In the present invention 2, preferred is apolyamide resin having a weight average molecular weight of 30,000 to150,000 and a softening point of 100 to 180° C.

Further, the molecular weight distribution of the polyamide resin is onefactor having some influence on the melting properties concerning theadhesive oozing. When the molecular weight distribution is narrow, theviscosity of the adhesive rapidly decreases under heat, and thetemperature range is narrow at which no adhesive oozes out during thebonding under heat and pressure. Therefore, it is preferred to use apolyamide resin having a broad molecular weight distribution, i.e., apolyamide resin having a weight average molecular weight/number averagemolecular weight ratio of 2 to 50.

When an polyamide resin having an amide group equivalent (molecularweight/one amide group) of 200 to 400 is used, the moisture absorptionproperties of the adhesive layer decrease, and a decrease in electricresistance due to moisture absorption can be prevented to the extentthat the degree of the decrease is one digit. Further, the humidityresistance including resistance to hydrolysis is improved. As a result,the insulation deterioration can be particularly preferably prevented.

There may be used a polyamide resin consisting of molecules in which thehydrocarbons each between amide groups have a molecular weight in a widerange of from 100 to 800, and a polyamide resin in which thehydrocarbons having different molecular weights each between amidegroups are irregularly arranged. These polyamide resins are preferred,since they have adhesion capability and high flexibility in spite oftheir large amide group equivalent.

The adhesive layer may further contain a phenolic resin. The phenolicresin is incorporated in an amount of 5 to 60 parts by weight per 100parts by weight of the polyamide resin. The adhesive layer may furthercontain an epoxy resin and an imidazole compound. The epoxy resin isincorporated in an amount of 9 to 88 parts by weight per 100 parts byweight of the polyamide resin. The imidazole compound is incorporated inan amount of 0.03 to 10 parts by weight per 100 parts by weight of theepoxy resin. The imidazole compound promotes the curing of the epoxyresin.

As a second variant, the present invention (to be referred to as thepresent invention 3 hereinafter) provides an adhesive tape for TABhaving an organic insulating film, an adhesive layer formed on theorganic insulating film, and a protection layer formed on the adhesivelayer, in which the adhesive layer contains at least epoxy resin havinga siloxane structure in its main chain.

The epoxy resin having a siloxane structure in the main chain isselected from a wide variety of known epoxy resins. Any epoxy resinhaving any structure can be used if its main chain is partly or whollyformed of a siloxane structure. The polymer constituting the main chainmay have a structure of any one of a homopolymer, a random copolymer anda block copolymer. The siloxane structure contained in the main chainmay be any one of a linear structure, a branched structure, a cyclicstructure and a combination of at least two of these. The number ofepoxy group(s) in per molecule of the epoxy resin is at least one, andit is not necessary to impose the upper limit on this number. In view ofthe compatibility of the epoxy resin with other resin and theenhancement of the crosslinking density of the cured adhesive, thenumber of the epoxy groups is preferably 3 or more.

The epoxy resin having a siloxane structure in the molecule, used in thepresent invention 3, can be obtained, for example, by polycondensing anorganosilicon compound (detailed below) with an epoxy compound having atleast 2 epoxy groups in the molecule.

The above organosilicon compound includes organoalkoxysilanes such asphenyltrimethoxysilane, diphenyldiethoxysilane, methyltripropoxysilane,phenylmethyldimethoxysilane, phenyldimethylmonomethoxysilane,dimethyldiethoxysilane and vinylmethyldimethoxysilane; silanes andsiloxanes such as tris(phenylmethylmethoxysiloxy)phenylsilane,1,5-dimethyl-1,3,5-triphenyl-1,3,5-trimethoxytrisiloxane,tris(phenylmethylmethoxysiloxy)vinylsilane and1,3-dimethyl-1,3-diphenyl-1,3-dimethoxydisiloxane; and siloxanes havinga molecular structure derived from the (co)hydrolysis of one or more ofthe above silanes and siloxanes and the polycondensation of theresultant (co)hydrolysis products and containing a hydroxyl group and/oran alkoxy group bonded to a silicon atom.

The above epoxy compound is required to contain at least 2 epoxy groups,and in addition to the epoxy groups, it may contain functional groupssuch as hydroxyl, alkoxy and vinyl groups.

Specifically, the above epoxy resin includes allyglycidyl ether,butylglycidyl ether, glycidyl methacrylate,3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate,vinylcyclohexenecarboxylate, vinylcyclohexene dioxide, dipentenedioxide, dicyciopentadiene dioxide,bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, diglycidyltetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidylphthalate, a phenol novolak epoxy resin, triglycidylisocyanurate,bisphenol A type resins such as bisphenol A diglycidyl ether obtainedfrom bisphenol A and epichlorohydrin, an epoxidized cresol novolakresin, and epoxy compounds obtained by partially modifying the aboveepoxy compounds with a fatty acid. Further, there may be co-used otherepoxy compounds having other structure such as epoxy resins modified byan elastomer such as NBR, SBR, Br and dimer acid.

The above epoxy resin having a siloxane structure may be allowed toreact with a polybasic carboxylic acid or an acid anhydride thereof.Specific examples of the polybasic carboxylic acid and the acidanhydride thereof include phthalic anhydride, isophthalic acid,terephthalic acid, maleic anhydride, fumaric acid, succinic acid,sebacic acid, adipic acid and tetrahydrophthalic anhydride.

The above adhesive layer may contain a curing agent for curing the aboveepoxy resin having a siloxane structure. The curing agent includes anovolak phenolic resin, a resol phenolic resin, diaminodiphenylmethane,diaminodiphenylsulfone, a polyamide resin, aromatic polyamine, aliphaticpolyamine and polyamideamine. These curing agents may be used alone orin combination. The curing agent is incorporated in an amount of 5 to700 parts by weight per 100 parts by weight of the epoxy resin.

In the present invention 3, the adhesive layer may further contain anepoxy resin having no siloxane structure in combination with the epoxyresin having a siloxane structure. The epoxy resin having no siloxanestructure is incorporated in an amount of approximately 10 to 16 partsby weight per 100 parts by weight of the epoxy resin having a siloxanestructure. The proportion of the epoxy resin having a siloxane structurebased on the total solid content of the adhesive layer is preferably 5to 50% by weight, more preferably 10 to 20% by weight. When thisproportion is less than 5% by weight, the water resistance of theadhesive layer decreases, and a decrease in the electric resistance dueto the presence of water is liable to occur. When this proportionexceeds 50% by weight, undesirably, an excess portion of the epoxy resinhaving a siloxane structure, which takes no part in the curing, ismigrated onto the adhesive layer surface to cause a decrease in theadhesion strength to a copper foil.

In the present invention 3, the adhesive layer may further contain atleast one member selected from thermoplastic resins such as a polyamideresin, a polyester resin, NBR, SBR and a polyvinyl acetal resin toobtain a cured adhesive layer having flexibility. Of these thermoplasticresins, a polyamide resin is particularly preferred, since it not onlygives a cured adhesive layer having flexibility but also works as acuring agent for the epoxy resin. The polyamide resin can be selectedfrom a variety of known polyamide resins. Of known polyamide resins,preferred are those having an amine value of at least 3 (preferably 5 to20), since these effectively work as a curing agent for the epoxy resinand improve the cured adhesive in adhesion strength, chemical resistanceand heat resistance.

In the present invention 3, the polyamide resin is used in an amount of100 parts by weight per 100 to 1,200. parts by weight of curingcomponents such as the epoxy resin, phenolic resin, etc., in theadhesive layer.

In the present invention 3, it is preferred to incorporate an imidazolecompound into the adhesive layer for acceleration of curing. Theimidazole compound is incorporated in an amount of 0.03 to 10 parts byweight per 100 parts by weight of the epoxy compound.

In the present invention 3, when the adhesive layer has a layerstructure formed of at least two layers, the epoxy resin having asiloxane structure in the molecule is required to be contained in thelayer in contact with the protection layer.

As a third variant, the present invention (to be referred to as thepresent invention 4 hereinafter) provides an adhesive tape for TABhaving an organic insulating film, an adhesive layer formed on theorganic insulating film, and a protection layer formed on the adhesivelayer, in which the adhesive layer contains at least one maleimidecompound.

In the present invention 4, it is preferred to incorporate at least oneof thermosetting components such as a phenolic resin and an epoxy resininto the adhesive layer in order to impart the adhesive layer withchemical resistance and heat resistance.

The maleimide compound used in the present invention includes a monomerhaving at least one maleimide group, a polymer obtained from themonomer, a polymer obtained from the monomer and a compound having anepoxy group, a polymer obtained from the monomer and a compound havingan amide group, a product obtained by reacting the monomer with an epoxyresin and a product obtained by reacting the monomer with a polyamideresin. For example, the above monomer includes bismaleimide of theformula (1), ##STR1##

wherein R is a divalent aromatic group.

Examples of the above monomer include N,N'-m-phenylenebismalelmide,N,N'-p-phenylenebismaleimide, N,N'-m-toluylenebismaleimide,N,N'-p-toluylenebismaleimide, N,N'-4,4'-bisphenylenebismaleimide,N,N'-4,4'- 3,3'-dimethylbiphenylene!bismaleimide, N,N'-4,4'-3,3'-dimethyldiphenylmethane!bismalemide, N,N'-4,4'-3,3'-diethyldiphenylmethane!bismaleimide,N,N'-4,4'-diphenylmethanebismaleimide,N,N'-4,4'-diphenylpropanebismaleimide,N,N'-4,4'-diphenyletherbismaleimide,N,N'-3,3'-diphenylsulfonebismaleimide, andN,N'-4,4'-diphenylsulfonebismaleimide.

As the maleimide compound used in the present invention 4, for example,a novolak-like arranged maleimide resin of the following (2) formula canbe used. ##STR2##

wherein n is an integer of at least 1.

Further, the maleimide compound used in the present invention can beselected from a maleimide resin having a siloxane structure and amaleimide resin having an aliphatic structure.

In the present invention 4, the above maleimide compounds may be usedalone or in combination. When the adhesive layer contains the abovethermosetting component, the maleimide compound is incorporated in anamount of 10 to 500 parts by weight per 100 parts by weight of thethermosetting component.

In the present invention 4, it is preferred to incorporate at least oneof thermoplastic resins such as a polyamide resin, a polyester resin,NBR, SBR and a polyvinylacetal resin to obtain a cured adhesive layerhaving flexibility.

In the present invention 4, the polyamide resin is preferably used in anamount of 8 to 100 parts by weight per 100 parts by weight of thethermosetting components such as the epoxy resin and the phenolic resinin the adhesive layer. The content of the maleimide compound based onthe total solid content in the adhesive layer is preferably 3 to 72% byweight, more preferably 5 to 20% by weight. When the maleimide compoundcontent is less than 3% by weight, the heat resistance is liable to beinsufficient. When this content exceeds 72% by weight, the flexibilityof the adhesive layer decreases, and the formed adhesive layer is toohard to retain the form of the adhesive tape for TAB.

In the present invention 4, the adhesive layer preferably contains animidazole compound for promoting the curing of the adhesive layer. Theimidazole compound may be used in an amount of 0.03 to 10 parts byweight per 100 parts by weight of the epoxy resin.

In the present invention 4, the adhesive layer has a layer structureformed of at least one layer. When the adhesive layer has a layerstructure of 2 or more layers, the maleimide resin is required to becontained in the layer in contact with the protection layer.

The epoxy resin used in each of the present inventions 1 to 4 isrequired to contain at least 2 epoxy groups in the molecule, and inaddition to the epoxy groups, the epoxy resin may contain hydroxyl,alkoxy and vinyl groups.

Specific examples of the above epoxy resin include allyglycidyl ether,butylglycidyl ether, glycidyl methacrylate,3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate,vinylcyclohexenecarboxylate, vinylcyclohexene dioxide, dipentenedioxide, dicyclopentadiene dioxide,bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, diglycidyltetrahydrophthalate, a phenol novolak epoxy resin,triglycidylisocyanurate, bisphenol A type resins such as bisphenol Adiglycidyl ether obtained from bisphenol A and epichlorohydrin, anepoxidized cresol novolak resin, and epoxy compounds obtained bypartially modifying the above epoxy compounds with a resin acid.Further, there may be co-used other epoxy compounds having otherstructure such as epoxy resins modified by an elastomer such as NBR,SBR, Br and dimer acid.

Examples of the phenolic resin used in each of the present inventions 1to 4 include bisphenol A type phenolic resins of which the phenolcomponent is formed from bisphenol A, alkylphenol type phenolic resinsof which the phenol component is formed from an alkyl phenol, resol typepheonolic resins obtained by co-polycondensing of these, and novolaktype phenolic resins. These phenolic resins may be used alone or incombination. The resol type phenolic resins obtained by polycondensingof alkylphenols includes those of which the phenolic hydroxyl groupshave methyl, ethyl, propyl, tert-butyl or nonyl in the o-position orp-position. These resol type phenolic resins are preferred since theyreact under heat to form insoluble and unmeltable solids, which improvethe adhesive layer in adhesion strength, insulation reliability,chemical resistance and heat resistance.

The polyamide resin which is preferably used in the present inventionsis selected from a variety of known polyamide resins. Particularlypreferred is a polyamide resin having an amine value of at least 3.0(preferably 5 to 20), since it effectively works as a curing agent forthe epoxy resin and improves the cured adhesive in adhesion strength,chemical resistance and heat resistance. The polyamide resin used in thepresent inventions preferably includes aliphatic polyamides and aromaticpolyamides having a weight average molecular weight of 2,000 to 150,000,a number average molecular weight of 500 to 8,000, a molecular weightdistribution (weight average molecular weight (Mw)/number averagemolecular weight (Mn)) of 2 to 50 and a softening point of 50 to 180° C.The above molecular weights (converted to a polystyrene basis) aremeasured by GPC, and the above softening point, by a ring and ballmeasuring method.

The imidazole compound preferably used in the present inventions 1 to 4includes 2-methylimidazole and 2-ethyl-4-methylimidazole which aresoluble in generally used solvents typified by methyl ethyl ketone, andit also includes 2-phenyl-4-benzyl-5-hydroxymethylimidazole which issparingly soluble in generally used solvents.

In each of the present inventions 1 to 4, the protection layer for theadhesive layer is a protection film of polyethylene, polyethyleneterephthalate or polypropylene.

In each of the present inventions 1 to 4, the adhesive tape for TAB isproduced as follows. FIG. 2 shows production steps, in which an adhesivehaving a predetermined composition is applied onto a protection film 3such that the dried layer thickness is 10 to 50 μm, preferably 15 to 30μm. In this case, the adhesive layer is required to be semi-cured. Forthis purpose, the applied adhesive is dried at 150 to 180° C. for 2minutes. Then, an organic insulating film 1 is stacked on theso-prepared adhesive layer 2, and attached thereto under heat at 100 to130° C. and pressure of at least 1 kg/cm². The resultant adhesive tapefor TAB is taken around a roll. For example, the adhesive tape for TABhas a width of 30 to 200 mm and a length of 30 to 300 m.

In the adhesive tape for TAB according to the present invention 1, theadhesive layer contains at least the above polyamide resin and epoxyresin, and the polyamide resin has a terminal amine value of at least3.0. Therefore, the adhesive layer does not show any decrease in theadhesion strength to a copper foil even if it is exposed to alkalis,acids or an etching solution in etching, plating and resist-peelingsteps. Further, the adhesive layer does not show any decrease in theadhesion strength to a copper foil and the organic insulating film at ahigh temperature when the inner lead bonding and outer lead bonding arecarried out.

In the adhesive tape for TAB according to the present invention 2, theadhesive layer contains the powdery inorganic filler. Therefore, thethermal expansion and contraction of the adhesive layer are inhibited,and the chemical resistance and heat resistance thereof are improved. Asa result, the adhesive layer is hardly corroded by an etching solutionand a plating solution used in a step of semiconductor device assembly,and the decrease in the adhesion strength of the adhesive layer to acopper foil can be prevented. The adhesive tape for TAB according to thepresent invention 2 has high insulation reliability and high adhesionstrength. Therefore, a pattern having a line width which is decreasingwith an increase in the number of lead pins and the organic insulatingfilm can be securely bonded, and there arises no problem on inter-leadinsulation properties. Therefore, that portion of the adhesive tape forTAB which is used for connection between a semiconductor chip and anouter electric circuit may remain in lead portions even if the number ofthe lead pins increases.

In the adhesive tape for TAB according to the present invention 3, theadhesive layer contains the epoxy resin having a siloxane structure inthe main chain, and the siloxane structure gives excellent waterrepellency, which prevents a water-induced decrease in electricresistance. Due to the epoxy resin having a siloxane structure In themolecule contained in the adhesive layer, the cured adhesive layer doesnot show any decrease in the adhesion strength to a copper foil evenwhen it is exposed to alkalis, acids or an etching solution in etching,plating and resist-peeling steps. Further, the adhesive layer does notshow any decrease in the adhesion strength to a copper foil and theorganic insulating film at a high temperature when the inner leadbonding and outer lead bonding are carried out.

In the adhesive tape for TAB according to the present invention 4, theadhesive layer contains the maleimide resin, and the structure of themaleimide resin characteristically gives excellent heat resistance.Further, the adhesive layer shows excellent resistance to chemicals suchas acids and alkalis. Therefore, the adhesive layer of the adhesive tapefor TAB according to the present invention 4 neither deteriorates insteps of etching, tin or gold plating, inner bonding, etc., nor causesthe peeling of a copper foil and the organic insulating film at a hightemperature. Further, due to the maleimide resin contained in theadhesive layer of the adhesive tape for TAB according to the presentinvention 4, the cured adhesive layer does not show any decrease in theadhesion strength to a copper foil even when it is exposed to alkalis,acids or an etching solution in etching, plating and resist-peeling.Further, since the maleimide resin structurally gives excellent heatresistance, the adhesive layer does not show any decrease in theadhesion strength to a copper foil and the organic insulating film at ahigh temperature when the inner lead bonding and outer lead bonding arecarried out.

Therefore, the adhesive tape for TAB according to any one of the presentinventions 1 to 4 can be applied to highly densified circuits. Whendevices having many input and output terminals are mounted, almost nobonding failure are caused, nor are leads deformed in carrying andbonding steps. The yields of devices therefore increase.

The present invention (inventions 1 to 4) will be explained hereinafterby reference to Examples, in which "part" stands for "part by weight".

EXAMPLE 1

A 38 μm thick protection film formed of a polyethylene terephthalatefilm was coated with an adhesive layer-forming coating compositioncontaining the following components, and the resultant coating was driedat 160° C. for 2 minutes to form an adhesive layer having a thickness of20 μm.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             400 parts                                         #509: amine value 7.0, weight average molecular weight                        35,000, molecular weight distribution (Mw/Mn) 8.3, softening                  point 120° C., supplied by Fuji Kasei Kogyo K.K.) in an                isopropyl alcohol/toluene mixed solvent                                       Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          50 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               30 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-methylimidazole in methyl                                                             0.3 part                                          ethyl ketone                                                                  ______________________________________                                    

Then, a 50 μm thick organic insulating film formed of a polyimide filmwas stacked on the adhesive layer and bonded thereto at 130° C. under apressure of 1 kg/cm².

Thereafter, the above protection film was peeled off, and a 1 oz/ft²electrolytic copper foil having a thickness of 35 to 40 μm was stackedon the adhesive layer and bonded thereto at 130° C. under a pressure of1 kg/cm². Then, the so-prepared laminate was consecutively heated at 60°C. for 6 hours, at 80° C. for 6 hours and at 150° C. for 5 hours to curethe adhesive layer, whereby a cured-adhesive tape was obtained.

EXAMPLE 2

Example 1 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             400 parts                                         #1350: amine value 10.0, weight average molecular weight                      37,000, molecular weight distribution (Mw/Mn) 6.7, softening                  point 152° C. supplied by Fuji Kasei Kogyo K.K.) in an                 isopropyl alcohol/toluene mixed solvent                                       Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          50 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               30 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-methylimidazole in methyl                                                             0.3 part                                          ethyl ketone                                                                  ______________________________________                                    

Comparative Example 1

Example 1 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             400 parts                                         #394: amine value 2.0, supplied by Fuji Kasei Kogyo K.K.)                     in an isopropyl alcohol/toluene mixed solvent                                 Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          50 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               30 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-methylimidazole in methyl                                                             0.3 part                                          ethyl ketone                                                                  ______________________________________                                    

(Test for evaluation of properties)

The cured-adhesive tapes obtained in Examples 1 and 2 and ComparativeExample 1 were tested for evaluation of the following properties.

1) Chemical resistance

The above-obtained tapes were evaluated as below on the adhesionstrength of the adhesive layer to the copper foil after immersion in anetching solution and an electroless tin plating solution.

Tape samples were subjected to etching (with an etching solutioncontaining ferric chloride as a main component) to form copper patternshaving a line width of 200 μm, 100 μm and 50 μm, and each sample wasmeasured for adhesion strength of the adhesive layer to the copperpattern. Separately, tape samples were etched In the same manner asabove, and electroless plated with tin, and each sample was measured foradhesion strength of the adhesive layer to the copper pattern. Table 1shows the results. The values for adhesion strength shown in Table 1were values for 180° peel strength obtained by means of a tension tester(Autograph AGS-100B, supplied by Shimadzu Corporation.

                  TABLE 1                                                         ______________________________________                                                 Pattern width                                                                          200 μm                                                                              100 μm                                                                              50 μm                                  ______________________________________                                        Example 1  After etching                                                                            30.8 g   14.7 g 7.3 g                                              After plating                                                                            30.8     14.5   6.9                                     Example 2  After etching                                                                            35.6     17.5   8.9                                                after plating                                                                            35.9     17.5   8.0                                     Comparative                                                                              After etching                                                                            30.6     13.8   6.9                                     Example 1  After plating                                                                            20.1      7.6   2.9                                     ______________________________________                                    

2) Adhesion under heat

A tape sample, on which a copper pattern having a width of 1 cm wasformed, was fixed to a hot plate having a temperature of 350° C. suchthat the organic insulating film was attached to the hot plate. Then,the sample was measured for its peel strength by peeling the copper foilin the 180° direction at a peel rate of 5 cm/min. Table 2 shows theresults.

                  TABLE 2                                                         ______________________________________                                                       Peel strength (g/cm)                                           ______________________________________                                        Example 1        290                                                          Example 2        340                                                          Comparative Example 1                                                                          70                                                           ______________________________________                                    

Tables 1 and 2 clearly show that the adhesive tape for TAB, provided bythe present invention, exhibits excellent chemical resistance andadhesion under heat.

EXAMPLE 3

A 38 μm thick protection film formed of a polyethylene terephthalatefilm was coated with an adhesive layer-forming coating compositioncontaining the following components, and the resultant coating was driedat 160° C. for 2 minutes to form an adhesive layer having a thickness of20 μm.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                              70 parts                                         TXC-232-C, Mw = 57,000, Mw/Mn = 10.4, softening point                         141° C., amine value 8.5, supplied by Fuji Kasei Kogyo K.K.)           in an isopropyl alcohol/water mixed solvent                                   Epoxy resin (Epikote 828, supplied by Yuka Shell                                                           6 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                                6 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 50% of a resol-type phenolic resin                                                             4 parts                                          (CKM-1282, supplied by Showa Kobunshi K.K.) in methyl ethyl                   ketone                                                                        Alumina (UA-5105, average particle size 0.4 μm,                                                         12 parts                                         supplied by Showa Denko K.K.)                                                 ______________________________________                                    

Then, a 50 μm thick organic insulating film formed of a polyimide filmwas stacked on the adhesive layer and bonded thereto at 130° C. under apressure of 1 kg/cm².

Thereafter, the above protection film was peeled off, and a 1 oz/ft²electrolytic copper foil having a thickness of 35 to 40 μm was stackedon the adhesive layer and bonded thereto at 130° C. under a pressure of1 kg/cm². Then, the so-prepared laminate was consecutively heated at 60°C. for 6 hours, at 80° C. for 6 hours, at 120° C. for 3 hours, and at150° C for 5 hours to cure the adhesive layer, whereby a cured adhesivetape was obtained.

EXAMPLE 4

Example 3 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                              70 parts                                         TXC-232-C, Mw = 57,000, Mw/Mn = 10.4, softening point                         141° C., amine value 8.5, supplied by Fuji Kasei Kogyo K.K.)           in an isopropyl alcohol/water mixed solvent                                   Epoxy resin (Epikote 828, supplied by Yuka Shell                                                           6 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                                6 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 50% of a resol-type phenolic resin                                                             4 parts                                          (CKM-1282, supplied by Showa Kobunshi K.K.) in methyl ethyl                   ketone                                                                        Solution of 1% of 2-ethylimidazole in methyl                                                               7 parts                                          ethyl ketone                                                                  Silica (Nipsil E220, average particle size 1.5                                                             12 parts                                         μm, supplied by Nippon Silica Industrial Co., Ltd.)                        ______________________________________                                    

Comparative Example 2

Example 3 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             100 parts                                         TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          8 parts                                           Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               8 parts                                           (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 50% of a resol-type phenolic resin                                                            6 parts                                           (CKM-1282, supplied by Showa Highpolymer Co., Ltd.) in                        methyl ethyl ketone                                                           Solution of 1% of 2-ethylimidazole in methyl                                                              10 parts                                          ethyl ketone                                                                  ______________________________________                                    

The cured adhesive tapes obtained in Examples 3 and 4 and ComparativeExample 2 were subjected to the following tests on their properties.

1) A pattern having a interpattern line interval of 100 Am was placedunder conditions where the temperature was 121° C., the pressure was 2atm., and the applied voltage was 100 V, and measured for a time untilan insulation failure occurred.

2) Chemical resistance (weight loss in acetone and methanol): Anadhesive layer-forming coating composition was cured under heat, andimmersed in acetone or methanol at 30° C. for 1 hour under theapplication of ultrasonic wave. Then, a weight loss (%) of the coatingcomposition was determined.

3) A TAB tape was measured for adhesion strength of the adhesive layerto a copper foil at room temperature (100 μm wide, peel direction at90°).

4) A TAB tape was measured for adhesion strength of the adhesive layerto a copper foil at a high temperature (250° C., 100 μm wide, peeldirection at 90°).

                  TABLE 3                                                         ______________________________________                                                                      Comparative                                                 Example 3                                                                             Example 4 Example 2                                       ______________________________________                                        1.  Time (hr) until                                                                             385       421     217                                           occurrence of                                                                 insulation failure                                                        2.  Chemical resistance:                                                          to acetone (%)                                                                              1.7       1.7     2.0                                           to methanol (%)                                                                             2.1       1.9     2.3                                       3.  Adhesion strength                                                                           1.7       1.6     1.4                                           at room temperature                                                           (kg/cm)                                                                   4.  Adhesion strength                                                                           1.2       1.1     0.8                                           at 250° C. (kg/cm)                                                 ______________________________________                                    

Table 3 clearly shows that the adhesive tape for TAB, provided by thepresent invention, exhibits high insulation reliability and excellentchemical resistance, and has high adhesion strength both at roomtemperature and at a high temperature.

EXAMPLE 5

A 38 μm thick protection film formed of a polyethylene terephthalatefilm was coated with an adhesive layer-forming coating compositioncontaining the following components, and the resultant coating was driedat 160° C. for 2 minutes to form an adhesive layer having a thickness of20 μm.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             50 parts                                          TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Epoxy resin having a siloxane structure (FM-5501,                                                         15 parts                                          diglycidyl polysiioxane resin of which the main chain was                     entirely formed of a siloxane structure, supplied by Chisso                   Corporation)                                                                  Solution of 50% of a novolak phenolic resin                                                               15 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                              15 parts                                          ethyl ketone                                                                  ______________________________________                                    

Then, a 50 μm thick organic insulating film formed of a polyimide filmwas stacked on the adhesive layer and bonded thereto at 130° C. under apressure of 1 kg/cm².

Thereafter, the above protection film was peeled off, and a 1 oz/ft²electrolytic copper foil having a thickness of 35 to 40 μm was stackedon the adhesive layer. Then, the so-prepared laminate was consecutivelyheated at 60° C. for 6 hours, at 80° C. for 6 hours, and at 150° C. for5 hours to cure the adhesive layer, whereby a cured adhesive tape wasobtained.

EXAMPLE 6

Example 5 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             50 parts                                          TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Epoxy resin having a siloxane structure (KF-101,                                                          15 parts                                          linear polyglycidyl polysiloxane resin of which the main                      chain was entirely formed of a siloxane structure, supplied                   by Shin-Etsu Chemical Co., Ltd.)                                              Solution of 50% of a novolak phenolic resin                                                               15 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                              15 parts                                          ethyl ketone                                                                  ______________________________________                                    

Comparative Example 3

Example 5 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             50 parts                                          TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          15 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               15 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                              15 parts                                          ethyl ketone                                                                  ______________________________________                                    

(Test on chemical resistance)

The cured adhesive tapes obtained in Examples 5 and 6 and ComparativeExample 3 were tested for evaluation of the following properties.

1) Chemical resistance

The above-obtained adhesive tapes were evaluated as below on theadhesion strength of the adhesive layer to the copper foil afterimmersion in an etching solution and an electroless tin platingsolution.

Tape samples were subjected to etching (with an etching solutioncontaining ferric chloride as a main component) to form copper patternshaving a line width of 100 μm, 50 μm and 30 μm, and each sample wasmeasured for adhesion strength of the adhesive layer to the copperpattern. Separately, tape samples were etched in the same manner asabove, and electroless plated with tin, and each sample was measured foradhesion strength of the adhesive layer to the copper pattern. Table 4shows the results. The values for adhesion strength shown in Table 4were values for 90° peel strength obtained by means of a tension tester(Autograph AGS-100B, supplied by Shimadzu Corporation).

                  TABLE 4                                                         ______________________________________                                                 Pattern width                                                                          100 μm                                                                              50 μm 35 μm                                  ______________________________________                                        Example 5  After etching                                                                            16.5 g   8.7 g  4.3 g                                              After plating                                                                            15.9     6.9    3.5                                     Example 6  After etching                                                                            15.6     7.2    3.8                                                after plating                                                                            15.1     6.5    3.1                                     Comparative                                                                              After etching                                                                             9.7     5.3    2.5                                     Example 3  After plating                                                                             8.6     4.6    1.9                                     ______________________________________                                    

2) Adhesion under heat

A tape sample, on which a copper pattern having a width of 1 cm wasformed, was fixed to a hot plate having a temperature of 300° C. suchthat the organic insulating film was attached to the hot plate. Then,the sample was measured for its peel strength by peeling the copper foilin the 90° direction at a peel rate of 5 cm/min. Table 5 shows theresults.

                  TABLE 5                                                         ______________________________________                                                       Peel strength (g/cm)                                           ______________________________________                                        Example 5        205                                                          Example 6        180                                                          Comparative Example 3                                                                          90                                                           ______________________________________                                    

Table 5 clearly shows that the adhesive tape for TAB, provided by thepresent invention, exhibits excellent chemical resistance and excellentadhesion under heat.

EXAMPLE 7

A 38 μm thick protection film formed of a polyethylene terephthalatefilm was coated with an adhesive layer-forming coating compositioncontaining the following components, and the resultant coating was driedat 160° C. for 2 minutes to form an adhesive layer having a thickness of20 μm.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                              50 parts                                         TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Solution of 20% of a maleimide compound (N,N'-                                                             15 parts                                         4,4'-diphenylmethanebismaleimide, BMI-S, supplied by Mitsui                   Toatsu Chemicals, Inc.) in dimethylacetamide                                  Epoxy resin (Epikote 828, supplied by Yuka Shell                                                           13 parts                                         Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                                13 parts                                         (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                               15 parts                                         ethyl ketone                                                                  ______________________________________                                    

Then, a 50 μm thick organic insulating film formed of a polyimide filmwas stacked on the adhesive layer and bonded thereto at 130° C. under apressure of 1 kg/cm².

Thereafter, the above protection film was peeled off, and a 1 oz/ft²electrolytic copper foil having a thickness of 35 to 40 μm was stackedon the adhesive layer. Then, the so-prepared laminate was consecutivelyheated at 60° C. for 6 hours, at 80° C. for 6 hours and at 150° C. for 5hours to cure the adhesive layer, whereby a cured-adhesive tape wasobtained.

EXAMPLE 8

Example 7 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

Solution of 25% of a polyamide resin (Tohmide

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                              50 parts                                         TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Solution of 20% of a maleimide compound (N,N'-m-                                                           15 parts                                         phenylenebismaleimide, BMI-MP, supplied by Mitsui Toatsu                      Chemicals, Inc.) in N,N'-dimethylacetamide                                    Epoxy resin (Epikote 828, supplied by Yuka Shell                                                           13 parts                                         Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                                13 parts                                         (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                               15 parts                                         ethyl ketone                                                                  ______________________________________                                    

Comparative Example 4

Example 7 was repeated except that the adhesive layer-forming coatingcomposition was replaced with a coating composition containing thefollowing components.

    ______________________________________                                        Solution of 25% of a polyamide resin (Tohmide                                                             50 parts                                          TXC-232-C, supplied by Fuji Kasei Kogyo K.K.) in an                           isopropyl alcohol/water mixed solvent                                         Epoxy resin (Epikote 828, supplied by Yuka Shell                                                          15 parts                                          Epoxy K.K.)                                                                   Solution of 50% of a novolak phenolic resin                                                               15 parts                                          (Tamanol 752, supplied by Arakawa Chemical Industries,                        Ltd.) in methyl ethyl ketone                                                  Solution of 1% of 2-ethylimidazole in methyl                                                              15 parts                                          ethyl ketone                                                                  ______________________________________                                    

The cured-adhesive tapes obtained in Examples 7 and 8 and ComparativeExample 4 were formed in TAB tapes in the same manner as in Example 5,and the resultant tapes were measured for property values (chemicalresistance and adhesion under heat) in the same manner as in Example 5.

                  TABLE 6                                                         ______________________________________                                                 Pattern width                                                                          100 μm                                                                              50 μm 35 μm                                  ______________________________________                                        Example 7  After etching                                                                            15.2 g   7.6 g  3.9 g                                              After plating                                                                            14.5     7.1    3.2                                     Example 8  After etching                                                                            14.9     7.3    3.3                                                after plating                                                                            14.2     6.8    3.0                                     Comparative                                                                              After etching                                                                             9.7     5.3    2.5                                     Example 4  After plating                                                                             8.6     4.6    1.9                                     ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                                       Peel strength (g/cm)                                           ______________________________________                                        Example 7        180                                                          Example 8        175                                                          Comparative Example 4                                                                          90                                                           ______________________________________                                    

Tables 6 and 7 clearly show that the adhesive tape for TAB, provided bythe present invention, exhibits excellent chemical resistance andexcellent adhesion under heat.

What is claimed is:
 1. An adhesive tape for tape automated bonding (TAB)having an organic insulating film, an adhesive layer formed on theorganic insulating film and a protective layer formed on the adhesivelayer, said adhesive layer being a layer containing a polyamide resinhaving an amine value of at least 3 and a powdery inorganic fillerhaving an average particle size of 0.1 to 3.0 μm and being at least oneoxide selected from the group consisting of silica, alumina,diatomaceous earth, titanium oxide, zinc oxide and magnesium oxide. 2.An adhesive tape for TAB according to claim 1, wherein the adhesivelayer contains 1 to 90% by weight of the powdery inorganic filler.
 3. Anadhesive tape for TAB according to claim 1, wherein the polyamide resinhas a weight average molecular weight of 30,000 to 150,000 and asoftening point of 100 to 180° C.
 4. An adhesive tape for TAB accordingto claim 1, wherein the adhesive layer further contains 5 to 60 parts byweight, per 100 parts by weight of the polyamide resin, of a phenolicresin.
 5. An adhesive tape for TAB according to claim 1, wherein theadhesive layer further contains 9 to 88 parts by weight, per 100 partsby weight of the polyamide resin, of an epoxy resin.
 6. An adhesive tapefor TAB according to claim 5, wherein the adhesive layer furthercontains 0.03 to 10 parts by weight, per 100 parts by weight of theepoxy resin, of an imidazole compound.